Teachers are working harder than ever before in several industrialised countries and are severely over-burdened in many parts of the developing world, according to the International Bureau of Education, a branch of the United Nations.
Class sizes and working hours have increased dramatically around the world, mainly due to government cost-cutting, an IBE report on pay and working conditions says.
The situation is most acute in many developing countries where an eagerness to ensure that all children go to primary school has resulted in large-scale recruitment of teachers.
Lack of money means that the recruitment drive has been accompanied by a serious decline in the profession's status as well as in its working and living conditions.
"In many African countries, it is not unusual to have classes of between 100 and 300 pupils. Of course teachers can't teach and children can't learn in these conditions. It's atrocious," says Victor Adamets, head of the IBE's studies unit.
Poor working conditions are only part of the problem. Teachers are often expected to struggle on desperately low pay, the IBE report says. Since their wages account for the bulk of education spending in all countries - 80 per cent in most and often 90 per cent in the least advanced - the principal means of reducing costs is by cutting salaries.
In many areas of the world, it is not unusual to find teachers at the bottom of the pay scale, forcing them to seek second jobs to make ends meet. Moreover, salaries are often paid irregularly, sometimes with a delay of several months.
"Education is one of the most important investments that each society can make for the future, yet in 1992, the estimate of global public spending on education as a percentage of gross national product barely exceeded 5 per cent," says the IBE. "The International Commission on Education for the Twenty-First Century set the target at 6 per cent of GNP," it adds.
There are no quick-fix solutions, says Mr Adamets, but persuading countries to make more efficient use of internal resources will help.
"It's a question of priorities. Experience shows that if governments are really inspired by political will to improve education, they find the money, " he says.